Question
Which of the following may be added to normal media to make it more selective for staphylococci? A. 7.5% salt B. 0.5% HCl C. 1.0% glucose D 5.0% mannose Approximately 90% of S aureus strains are resistant to A. methicillin. B. tetracycline C. polymyxin B. D. penicillin. In addition to S. aureus, impetigo may also involve A. Micrococcus luteus. B. Streptococcus pyogenes. C. Staphylococcus epidermidis. D. Pseudomonas spp. In which of the following does a rash start on the palms and soles and progress toward the trunk? A. epidemic typhus B. typhoid C. Lyme disease D. impetigo E. Rocky Mountain spotted fever The causative agent of Lyme disease is A. Rickettsia rickettsi B. Rickettsia prowazeki C. Borrelia burgdorferi. D. Dermacentor andersoni. The unique characteristic of Lyme disease is A erythema migrans. B induration. C. carbuncle. D. furuncle. A common viral rash of childhood with the popular name chicken pox is also known as A. bariola. B. rubella. C. rubeola D. varicella. Reactivation of chickenpox usually at advanced age is called A. shingles. B. Herpes zoster. C. pneumonia. D. Varicella zoster E. A or B are applicable
Explanation / Answer
Ans- A
Manitol salt agar media contains 7.5% NaCl which makes it selective for Gram +ve bactria.
Ans-31
More than 90% of Stayphalococcus isolates
resistant ti penicillin. This resistance ti penicillin is mediated by beta-lactamase enzyme (blaZ gene which encodes this enzyme when staphyloccus exposed to beta-lactam) which hydrolyze beta-lactam antibotics, rendering beta-lactam inactive.
Ans-32 (B)
Impetigo is most common skin infection in children. It is caused by two bacteria
Streptoccus pyogens and S.aureus.
Ans-33 (E)
Rocky Mountain Spotted fever
Ans-34 (A)
Tick borne illness caused by bacterium Borrelia burgdorferi
Ans-35 (A)
In lyme disease common sign of infection is redness at the of tick bite , known as erythema migrans.
Ans-36 (D)
Chickenpox is also known as varicella.
Ans-37 (A)
Shingles